1. Field of the Invention
The present invention relates to a humidity detector which is provided in, for example, a microwave oven or the like to detect, through the steam, the finished condition of the material to be cooked.
2. Description of the Prior Art
Conventionally, a humidity sensor to be used in, for example, a microwave oven, had two thermistors self-heated; one of them was sealed in dry air of 0 g per m.sup.3 in absolute humidity, the other thereof was adapted to receive the air to be discharged from within the heating chamber. However, this type of humidity sensor required two thermistors, as a pair, approximately equal in temperature coefficient and resistance value at the high temperature, thus resulting in higher cost. Also such a humidity sensor was incapable of varying the detection characteristics, so that a humidity sensor was desired which was capable of adjusting the detection characteristics for each of the microwave ovens because of variations in the volume within the electronic range, the air flow of the motor or the like.